Intonation refers to the variation in pitch when speaking, which conveys meaning, emotion, and emphasis. In language learning, intonation is crucial for effective communication, as it can change the meaning of a sentence, indicate questions, show politeness, or express emotions. Teaching intonation involves helping learners recognize and produce different pitch patterns through activities such as listening exercises, mimicking native speakers, and practicing dialogues. Mastery of intonation improves learners' spoken fluency and ability to convey subtleties in meaning.